So far in a polymerization reaction of a conjugated diene polymer and a conjugated diene copolymer prepared by solution polymerization, there was a problem that heat of the reaction increases as catalyst is added to monomer solution, thereby increasing a reaction temperature, and in particular, if the reaction temperature exceeds a boiling point of the monomers, boiling starts abruptly, which is dangerous. Particularly, the case of preparing a liquid polymer using a large amount of catalyst is so much the worst.
In order to cope with such a problem, in conventional solution polymerization reaction, a pressure resistant reaction vessel has been used from safety point of view. Further, as countermeasures to be taken in view of safety, not only use of a pressure resistant reaction vessel but also use of pressure resistant equipment for transferring materials which withstands an inner pressure or cooling equipment for controlling the reaction temperature was required, which lead to a problem that equipment cost increases. Furthermore, in order to inhibit abrupt generation of heat of reaction, it was necessary to limit an amount of catalyst to be used.
Myrcene is a natural organic compound and is a kind of olefin belonging to monoterpene. There are two kinds of isomers as myrcene such as α-myrcene (2-methyl-6-methyleneocta-1,7-diene) and β-myrcene (7-methyl-3-methyleneocta-1,6-diene), and when simply referring to myrcene, it usually indicates the latter one. In Patent Document 1, a polymer of myrcene is disclosed.
Farnesene is a kind of isoprenoid compound synthesized chemically by oligomerization of isoprene or dehydration reaction of nerolidol, and is used mainly as a perfume or its starting material (Patent Document 2).